Electric signaling system



s. B. H ESS. ELECTRIC SIGNAL ING SYSTEM.

APPLICATION .FlLED. JAN- 21,1918.

Pa tentedSept'. 19,1922.

INVENTOR s. Bnmzss. ELECTRIC S|G.NAL ING SYSTEM. APPLICATION FILED JAN-21,1918.

'1,429,24s6 I PdtentedSept- 19,19 2.

3 SHEETS-SHEET 3.

Patented Sept, l9,

SIMON nnnss, or JAMAICA, NEW YOR ELECTRIC SIGNALING SYSTEM.

' Application filed January 21, 1918. Serial no. 213,111. I

To aZZ whom it may concern:

Be it known that I, SIMON B. Hnss, a citi- Zen of the United States, residing at Jamaica, in the county of Queens and State of New York, have invented certain new and useful Improvements in Electric Signaling Systems, of which the following is a specification.

The system disclosed by this application is particularly adapted for utilization as an alarm system for protecting, say, from fire, a group of buildings such as the associated buildings of a public hospital or other public institution.

From the standpoint of providing a system which in case of fire will tend to provide safety to the lives of the occupants, the entire institution should be considered as being made up of units, each of which may be either a section of a building (setofi' by a fire wall), or a whole building in which in case or" fire therein all the occupants would be in danger and should be apprised of the danger by the operation of the alarm system.

In order that the attendants and help may know of a fire in any of the units, the signal receiving devices in the buildings occupied by them should be connected to a general alarm circuit, to receive signals from any unit. in case of a fire in any of the units, a

signal should be sounded in that unit and also in the buildings on the general alarm circuit, so that the helpless occupants of the endangered unit maybe removed to a place of safety, and the fire may be attacked'and extinguished.

The system disclosed herein is so designed that a signal can be sent from any section o'l any unit by the fire signal box in that section, notifying the occupants of the unit and also the attendants on duty in other i I n r. n a re rtin l ulldings, an l indlcitin o 00 l g a paratus 1n the (rentral station the location of the particular box operated.

ceiving devices of that unit and not in any other unit except those that are on the genoral alarm circuit.

It preferred, the signal receiving devices other loops.

The signal boxes 0'! each unit operate the signal re-' The system disclosed by this invention is so arranged that when more than one loop of signal receiving devices is connected to one relay, any 'loopmay be broken without preventing the receipt of a signal by the The system disclosed by this invention is also so arranged that, when connected to the usualdirect current power system, which has one conductor grounded, a ground upon any part of the system cannot increase the flow of current through any or the apparatus to I an extent sufiicient to damage the same.

A time limit device which has certain novel, features is also provided and is arranged to open the fire signal circuit in the event of continuousfiow of thesignaling current, before this current has continued long enough to damage any apparatus.

In order thatmy invention may be better understood, I show in-thedrawing annexed the clearer illustration of my invention 'and is intended not to be interpreted in a, limiting sense.

For clearness, Fig-l has'been made. in two parts, Fig. l to the right, and Fig. 1 to the left. placed adjacent to each other, the corre-' spending lines in the two parts are to be assumed continuous from one sheet to the other;

position in Fig.-1. I i

Figures 1 and 1 represent the equip ment in three different buildings, building A containing signal boxes or signal sending 1 devices 90, the mastercontrolboard 20 and various general alarm. signal recelving devices, building B containing a signal sending device, a unit control board 20 and varlous unit signal receiving d8VlC6S,' and building C containing only general alarm signal receivingdevices and asignalsending devlce;

When the two sheets are so,

'85 shown in the annexed drawing is given for Fig. 2 is a detail to be hereinafter explained, and Fig. 3 is an{ isometric dr'awing of a'possible construction for the threemagnet shown diagrammatically The, source of energy ll is shown as 10- i cated in building 11. and is represented as a direct current generator, one terminal of which is connected to conductor 13, and the other terminal of which is connected to conductor let and ground 12. Conductor 13 is connected to non-grounded terminal 21 of master control board and non-grounded terminal 21 of unit control board 20 by conductors 13 and 13 respectively. Conductor lt is connected to ground terminal 22 of mastercontrol board 20 and ground terminal 22 of unit control board 2O by conductors 14tand 14L respectively. Other control boards would be similarly connected, and might all be located in the central station containing the master control board 20 source of energy 11, recording apparatuslf), trouble signal annunciato'r 18, etc."

The trouble annunciator 13 is shown as located in building A and is connected to trouble terminal 26 of master control board terminal to conductor 17,'which leads to annunciator 1S. Conductor 15 is connected to trouble terminal 25 of master control board 20 and trouble terminal 25 of unit control board 20 by conductors 15 and15 respec tively. It is evident that other control boards would be connected to the annunciator in a corresponding manner.

In Fig. 3, the electromagnet coils 7 5 and 77 are provided with cores 87 and 7%, respectively. Cores 87 and 7d extend through insulating piece 115 and are provided withguide pins 132 and 131 respectively. EX- tending back from the front-edge of insulating piece 115 are two recesses, the contact spring 71 andthe upper spring of the switch 73 being mounted on piece 115 above these recesses. Contact spring 69 and the lower spring of the switch 73 are so mounted on piece 115 below the recesses as to be capable of engagement with contact spring 71 and the upper spring of the switch 73, respectively. Armature 116 is adapted to slide upon the guide pins 131 and 132 and has attached thereto the guide pin 130' and the insulating piece 72. This insulating piece and insulating piece 72 support the contact blocks 45 and 52. Contact block 45 extends toward the upper spring of the switch 73, being provided with an insulating end 45 adapted to abut against said upper spring. Contact block 52- extends toward contact spring 71, being provided with an extension 52', adapted to abut against contact spring 71. Guide pin 130 has attached thereto the operatingmember of the switch 90.

When armature 116 is in its fully retracted position, contact blocks 45 and 52 are adapted to engage with contact blocks 44:

1 ,eeeme and 56, respectively, mounted on the insulating piece 129, through which guide pin 30 is adapted to pass. When armature 116 is in its intermediate operative position (as shown in the figure), insulating end &5 touches the upper spring of the switch 73, which is also touching the lower spring of said switch, and extension 52 touches contact spring 71, which is also touching contact spring 69. Switch 90 is open. When armature 116 is in its fully attracted position, insulating end 15 holds the upper spring of the switch 7 3 away from the lower spring thereof, and extension 52 holds contact spring 71 away from contact spring 69.

From a consideration of the above described construction it is evident that while a certain current will be suflicient to move armature 116 from its fully retracted. position to its intermediate operative position, the added resistance due to spring 71, the upper spring of the switch 73, and the upper springs of the switch 90 will require the passage of a considerably increased current in order to cause the armature to more from its intermediate operative position to its fully attracted position.

United States Patent No. 1,066,432 issued to Kettering under date of July 1, 1913, shows another construction which may be adapted to the same purpose.

On each control board -is mounted an electromagnet, having the coils 75 and 77, provided with cores 87 and 7 1, respectively. The armature (not shown) of each electromagnet has secured thereto the insulating piece 72 which is adapted to control certain contact devices, as will be hereinafter explained. The time limit device mounted upon each control board comprises the heat ing unit 39, the fuse 40, and the spring 36. Fig. 2 shows a side elevation thereof. One end of the fuse 40 is secured to the spring 36 and the other end to the stud 41. The spring 36 has therein a slot 37 through which the headed post 38 is adapted to pass, and. tends to straighten itself downwardly and away "from the stud 421. When fuse 10 is not secured to thetree end of spring the spring will move downwardly and outwardly until stopped by the end'ot slot 37 therein coming in contact with post 33, or by the spring 36 coming in contact with the head 01 post 38, depending upon the relative arrangement 01 the parts T he stud a1 and the spring 36 are so arranged with relation to the heating unit 39 that the spring 36 is under tension and the fusible part of the fuse 40. is held against the heating unit, so that when the use is softened by the heat of the heating unit, the spring 36 will move (as permitted by the slot 37) downwardly and outwardly, carrying with it the lower portion of the fuse 10, thus producing a rapid interruption of the circuit through the fuse,

the combined force of gravity and the spring 36 acting to draw the lower end of the fuse out of contact with the heating unit. Resistance units 8485 and 86 are provided, resistance unit 84-85 being used to diminish the current flow through the box or signal. sending loop, and resistance unit 86 being provided when there is not enough resistance in the gong or signal receiving loop connected thereto.

Referring particularly to master control board 20 the contacts controlled by insulating piece 72 and the extensions thereof are so arranged that when the armature is in its fully retracted position contact block 44 is in engagement with contact blocks 45, 46, 47 and 48, contact block 56 is in engagement with contact blocks 52, 53, 54 and 55, switches 49, 50 and 51 are open, switch 73 is closed, and contact spring 71 is in engagement with contact spring 69 and out of engagement with contact spring 70. Upon movement of the armature away from its fully retracted position contact blocks 44 and 56 will move out of engagement with their cooperating contact blocks. It is obvious that at a certain intermediate position in the movement of the armature from its fully retracted position toward its fully attracted position (herein called its intern'iediate operative position) switches 49, 50 and 51 will be brought to closed circuit condition, and it is evident that while a certain current will be sufficient to move the armature from its fully retracted position to its intermediate operative position, the retractile force added by these switches will require the passage of a considerably increased current in order to cause the armature to move from its intermediate operative position to its fully attracted position. in the intermediate operative position contact spring 69 is in engagement with contact spring 71 and switch 73 is closed. When the armature is in its fully. attracted position (the position of Fig. 1 switches 49, 50 and 51 are closed and contact spring is in engagement with contact spring 71, all the other contacts being open.

Referring particularly to unit control board '26 the contacts controlled. by insulating piece 72 are so arranged that when the armature is in its fully attracted position (the position of Fig. 1*), signal sending switch 90 is closed and contact spring 71 is in engagement with the extension of contact block 52, all the other contacts being open. When the armature is in its intermediate operative position contact spring 69 is in engagement wi'thjcontaet spring 71 and switch 73 is closed. The resiliency of the parts of switch 90 is such that this switch is closed. All the other contacts are open. When the armature is in its fully control board 20*, conductor 35, time limit spring 36, time limit fuse 40, stud 41, conductor 80, resistance 84, conductor 83, conductor 43, time limit heating unit 39, conductor 42, balancing unit 86, conductor 60, terminal 34 of the first signaling receiving device loop, conductor 88, bells 89, conductor 92, terminal 33 of the first signal receiving device loop, conductor 64, switch 51, conductor 59, terminal 32 of the second signal receiving device loop, conductor 93,'the signal receiving devices in this loop, conductor 94,: terminal 31 of the second signal receiving. device loop, conductor 63, switch 50, conductor 58, terminal 30 of the third signal receiving device loop, conductor 95, bells 89, conductor 96, terminal 29 of the third signal receiving device loop, conductor 62, switch 49, conductor 57, terminal 28 of the fourth signal receiving device loop, conductor 97, the signal receiving devices in this loop, includingrecording apparatus 19, conductor 98, terminal 27 ofthe fourth signal receiving device loop, conductor 61, conductor 65, contact spring 70, contact spring 71, conductor 78, terminal 24 of the signalsending loop, conductor 91, boxes or signal sending devices therein, terminal B of the unit control board 20", conductor 99, switch or signal sending device 90, conductor 100, terminal B of the unit control board 20 conductor 91*, signal sending device 90 in building C therein, terminal 23 of'the signal sending loop of master control board 20 conductor 82, coil 77, conductor 76, coil 75, conductor 67, conductor 68, ground :ter-

resistance 5 minal 22, conductor 14, conductor 14, to

ing unit 39, stud 41, time limit fuse 40, time limit spring 36, conductor 44, conductor 80, resistance 84, conductor 83, balancing resistance unit 86, conductor 60, terminal 34 of the signal receiving device loop, conductor 88, bells and lamps 89, conductor 92, terminal 33 of the signal receiving device loop, conductor 64, flexible connection 52, contact block 52 and the extension thereof,

7 71, conductor 76, lern'iiual "nal sending loop, conductor 9.1", signal striding devices 90 therein, terminal 23 of the senc ing loop, conductor 82, coil 7 5, conductor 76, coil 77, conductor 67, ground terminal 22, conductor 14, conductor 14-, to grounded terminal of generator 11.

The winding of coils 7 5 and 77 in each circuit is so related to that ol? the signal receiving devices 89 that the current passing through the circuits just described is sull'h cient to cause the armature associated with coils and 77 to be moved to its fully attracted position, while the signal receiving devices give no indication upon this current strength. While coils 75 and 77 a re themselves of comparatively high resistance, resistance 64% in series therewith assists in securing a minimum value tor the normal current flow after the armature associated with coils 75 and 77 has been moved to its fully attracted position.

lit has perhaps been noticed that the same reference numeral 90 has been used "for the signal sending switch controlled by the elec tromagnet of the unit control board 520 for the boxes or signal sending devices in the signal sending loop of the unit control. board 20 and for the boxes or signal sending devices in the signal sending loop of the master control board 20. This has been done to carry out the idea that the same electrical function is performed, whether the signal sending device is operated by a manually wound clockwork or by an electromagnet.

Tn botl" Figs. 1 and 1 the conductor 80, resistance 85, conductor 66, and contact spring 69 comprise an open shunt across the signal receiving loops.

In the case of a lire in any unit, as for example, in the particular unit associated with the unit control board 20 the pulling of the box 90 will break the signal sending loop, and the consequent retraction of the armature of the electromagnet'ot the unit control board 2O will result in the establishment of the following circuits :--(1) from conductor ll, to contact block 44:, contact block 45, flexible connection 4,-5", conductor 45 (thus shortcircuiting resistance 8 t), balancing resistance unitfiG, conductor 60, terminalB-lv oi the signal receiving device loop, conductor 88, bells and lamps condru-tor 92, terminal 33 of the signal receiving device loop, conductor 6t, flexible connection 59), contact block 52, contact block 56, con ductor 68, to ground terminal 22; from conductor a l, to conductor 80, resistance 85, conductor 66, contact spring 69, contact spring 71, conductor 78, terminal 24: of the signal sending loop, conductor 91 to operated box (now open here), terminal 28 of the signal sending loop, conductor 82, coil 75, conductor 76, coil 77, conductor 67,

to ground terminal 22; from lett hand. terminal of trouble battery 16, to conductor 17, annunciator 18, conductor 17, terminal 26 of unit control board 20 conductor 79, switch 73, conductor 81, terminal 25, conductor 15", conductor 15, to right hand terminal of battery 16.

It Will be seen that in circuit (1) the signal. receiving device loop is now connected to the terminals of the source of energy 11 with no intervening resistance except that of the line conductors. The bell magnets are so constructed and arranged. that their armatures are now effectively attracted to sound a stroke of the signal. The lamp is so constructed and arranged that its l'lla ment is effectively illuminated to give a visual indication of the signal. As shown, the signal receiving devices are connected in rice. It devices of a standard resistance and intended for a standard current strength are used, it is evident that the number of them which should be connected in. any signal receiving device loop depends upon the voltage of the supply circuit. F or example, it it be assumed that heating unit 39 has a resistance of 5 ohms, and that the signal receiving devices 89 each have a re sistance of 5 ohms and require a current of 3 amperes for ellicient operation, it is evident that a maximum of 7 signal receiving devices may be connected in the signal receiving device loop. VVhenever the number of devices required for any particular unit is not as great as the number corresponding to the supply voltage available, the balancing resistance unit 86 is used. If any unit requires more devices than the number corresponding to one signal receiving device loop, that is, to a single loop control board of the type represented by 20, use may be made of a control board having more than one loop. As 20 represents a four-loop board, it is evident that a three-loop board would be similar except for the omission of switch 49, contact blocks 53 and 4:6, and terminals 27 and 2S, and that a two-loop board would further omit switch 50, contact blocks 54: and a7, and terminals 29 and 30 The closing of circuit causes the operation of the corresponding section of the trouble annunciator and the ringing of its bell, which continues as long as the armature of the electromagnet remains out of its fully attracted position. 7

The retraction of the armature oil the electromagnet of unit control board 20 will also cause the opening of switch 90 controlled thereby, which will break the signal sending loop of the master control board 1 20, and the consequent retraction ot the armature of the electromagnet of the master control board 20 will result in the establishment of the following circuits: (1) from stud ll on master control board 20*, to

flexible connection 4 1 contact block 44, contact block 45 (thus shortcircuiting resistance 8 1), conductor 13, time limit heating unit 39, conductor 42, balancing resistance unit 86, conductor 60, terminal 34 of the first signal receiving device loop, conductor 88, bells S9, conductor 92, terminal 83 of the first signal receiving device loop, conductor 64, contact block 55, contact block 56, flexible connection 56, to conductor 68; from stud tl on master control board 20, to flexible connection l contact block a l, contact block 48, conductor 59, terminal 32 of the second signal receiving device loop, conductor 93, the signal receiving devices in this loop, conductor 94, terminal 31 of the second signal receiving device loop, conductor 63, contact block 5%, contact block 56, flexible connection 56 to conductor 68; from stud 41 on master control board 20*, to flexible connection as contact block 4 1, contact block 47, conductor 58, terminal 30 of the third signal receiving device loop, conductor 95, bells S9, conductor 96, terminal 29 of the third signal receiving device loop, conductor 62, contact block 53, contact block 56, flexible connection 56, to conductor 68; (4) from stud ll on master control board 20", to flexible connection 449, contact block 4.4, to contact block 46, conductor 57, terminal 28 of the fourth signal receiving device loop, conductor 97, the signal receiving devices in this loop, including recording apparatus 19, conductor 98, terminal 27 of the fourth sig nal receiving device loop, conductor (31, contact block 52, contact block 5'3, itie-xible connection 56 to conductor 68; from stud tl on master control board 20, to conductor 80, resistance 85, conductor 66, contact spring 69, contact spring 71, conductor 78, terminal 24 of the signal sending loop, conductor 91 boxes therein, terminal 13 of the unit control board 20 conductor 99,

switch 90 (now open here), conductor 100, terminal 13 of the unit control board 20 conductor 91 box 90 in building C therein, terminal 28 of the signal sending loop of master control board 20, conductor 82, coil 77, conductor 76, coil 75, conductor 67, to conducter 68; (6) from left hand terminal of trouble battery 16, to conductor 17, annunciator 18, conductor 17 terminal 26 of master control board 20, conductor 7 9, switch 73, conductor 81, terminal 25, conductor 15, conductor 15, to right hand terminal of battery 16.

It will be seen that in circuits (1), (2), (3), (a the signal receiving device loops are now connected to the terminals of the source of energy 11 with no intervening 1 sistance except that of the line conductors. The magnets oi the bells and of the recording apparatus are so constructed and arranged that their armatures are now effectively attracted to sound and record a stroke of the signal. The closing of circuit (6) causes the operation of the corresponding section of the trouble annunciator and the ringing of its bell, which continues as long as the armature of the electromagnet remains out of its fully attracted position.

When circuit (2) of unit control board 20 is closed at the operated box 90, the armature of the unit controlboard electromagnet is attracted and reestablishes its normal closed circuit. As this movement of the armature also closed' the switch 90 on the unit control board 20 thus closing circuit (5) of the master control board 28, the armature of the master control board electromagnet is attracted and reestablishes its normal closed circuit.

As each succeeding break of the signal sending loop of the unit control board will have a corresponding effect, it will be seen that the signal sent by this box will be indicated by the signal receiving devices of that unit and also by the signal receiving devices controlled by the, master control board (the general alarm receiving devices). The trouble annunciator- 18 indicates in the central station the particular unit operated, and also gives an indication for the master control board, while'the recording apparatus 19 makes apermanent record of the number of the particular box operated.

As each unit would be correspondingly equipped and connected, it will be seen that in case a box is pulled in any unit, the signal will be sounded in that unit and also in the buildings on the general alarm circuit. As the master control board does not repeat back to the unit control boards, it will be seen that the signal boxes of each unit do not operate the receiving devices in any other unit, except those that are on the general alarm circuit. It will also be seen that a box on the signal sending loop of the master control board may be operated (as for a' fire drill) without operating any signal receiving devices except those on the general alarm circuit.

In the case of a break or a. ground in the signal sending loop of any unit control board the armature of the magnet thereof will be fully'retracted, a single stroke will be indicated upon the signal receiving devices of that unit control board and also of the signal receiving devices controlled by the master controlboard, and the trouble annunciator will indicate both the particular unit control boad which is in trouble and the master control board. In the case of a break or a ground in the signal sending loop of the master control board the armature of the magnet thereof will be fully retracted, a single stroke will be indicated upon the signal receiving devices controlled by the master control board, and the trouble 'annunciator will indicate the master control board.

In the case of a break in the signal receiving device loop of any unit control board the armature of the magnet thereof 'will move to its intermediate operative posiwhich is in trouble, andthe engagement of contact spring 69 with contact spring 71 completes circuit (2) causing the armature to be moved toward its fully attracted position, and when circuit (2) is broken at con tact spring 71 a vibrating action will be set up. A break in a signal sending loop produces a result difl erent from a break in a signal receiving loop because in the case of a break in a signal sending loop circuit (2) is open at the break and the magnet is not reenergized, while in the case of a break in a signal receiving loop the flow of current through circuit (2) reenergizes the magnet and starts the vibrating action. Correspondingly, in the case of a break in any signal receiving device loop of the master control board or of any multiple signal receiving device loop unit control board the armature 'of the magnet of the affected board will vibrate and the trouble annunciator will indicate the affected board. As the armature of any unit control board does not move far enough toward its fully retracted position to open its switch 90 it is evident that the masits fully retracted position to close any of vices in other loops will be energized.

its signaling circuits, no signal receiving de- A the armature will move to its fully retracted position when its signal sending loop is broken by the operation of a signal boX, it will be seen that when more than one loop of signal receiving devices is connected to one relay, any loop may be broken without preventing the receipt of a signal by the other loops.

In the case of a ground upon the signal receiving device loop of any unit control board the armature of the magnet thereof will move to its intermediate operative position, closing circuit (3) for the trouble annunciator and completing circuit (2) causing the armature to be moved toward its fully attracted position and when contact is made between the extension of contact block 52 (which is connected to the grounded signal receiving deviceloop) and contact spring 71 a vibrating action will be set up. it ground upon a signal sending loop produces a result different from a ground upon a signal receiving loop because in the case of a ground on a signal sending loop circuit (2) is grounded and the magnet is not reenergized, while in the case of a ground upon a signal receiving loop the flow of current through circuit reenergizes the magnet and starts the vibrating action. Correspondingly, in the case of a ground on any signal receiving device loop of the master control board or of any multiple signal receiving device loop unit control board the armature of the magnet of the affected board will vibrate and the trouble annunciator will indicate the affected board. As the armature of the control board electromagnct does not move far enough toward its fully retracted position to short-circuit resistance 84, it will be seen that, upon whatever part of the system a ground occurs, a certain definite resistance will always be included in the circuit between the non-grounded terminal of the source of energy and the ground, i. e either resistance 84- or resistance 85, and the values of these resistances may be so selected that the flow of current through any of the apparatus cannot increase to an extent sufficient to damage the same.

Referring to control board 20 it will be seen that time limit heating unit 39 and time limit fuse 40 are located in the path of the normal closed circuit, and are also traversed by the signaling current. Resistance 39 is of such value, and the fusible part of time limit fuse 4:0 is made of such alloy and such cross-section, that the normal. closed circuit current flow will have no operative effect. However, if the heavier signaling current continues to flow for more than a certain length of time, the heating of heating unit 39 thereby will be such that the alloy of the time limit fuse ll) will be softened and the time limit spring 36 will. move to pull the fuse apart, thereby producing a rapid interruption of the circuit through the fuse. From an inspection of Fig. 2 it is evident that the force of gravity will tend to retain the upper portion of the fuse 10 in contact with the resistance 39, while the force of gravity and the spring 36 will tend to draw the lower end of the fuse out of contact with the heating unit. It will be noticed that the different parts of the time limit levice are so connected that the portion of the fuse remaining in contact with the resistance is of the same polarity as the resistance, hence the are caused by the operation of the fuse has no tendency to break down the insulation resistance of the heating unit and to cause a flow of current directly from the fuse to tire resistance.

lOO

Referring to control board 20 (and correspondingly to any other multiple signal receiving device loop board), it will be seen that time limit heating unit 39 and time limit fuse 40 are located in the path of the normal closed circuit, and that while fuse 10 is traversed by the entire signaling current, heating unit 39 is traversed only by the signaling current for one loop. The operation is the same as with control board 20 the heat from heating unit 39 in one loop causing the softening of the fuse 40 and the interruption of the current for all loops. As the current carrying capacity of fuse 40 itself is far in excess of the total signaling current for the maximum number of loops which would be connected to any one control board, and as heating unit 39 is traversed by the signaling current for one loop only (which would be the same, whether on a single loop board or on a multiple loop board), it will be seen that heating unit 39 and fuse 40 may be standardized for'all control boards. I 1

When the usual type of dual operation" or pre-signal system is installed, that is, when more than one signal receiving device loop is connected to one control board and the circuits are so arranged that discretion may be exercised as to the number of these loops which shall receivethe signaling current (such a system .being shown in the Francis Patent No. 1,239,381, issued Sept. 4t, 1917), it is evident that the time limit device therein shown is defective in opera-- tion, because the heating unit is so connected in the circuit that the entire signaling current passes therethrough. As this current under one condition of operation will be approximately double what it will be under another condition of operation, the heating effect thereof under one condition of operation will be approximately four times what it will be under another condition of operation, and it is evident that the time required for the operation of the time limit device under these different conditions will be subject to extreme variations. lVhen the time limit device is connected in the manner herein shown and described, this objectionable feature is avoided, as the time required for operation does not vary with the variation in the total current flow, but is practically. constant.

This application is a continuation in part of my patent issued august 31, 1920, No. 1,351,514, reissued December 14, 1920, No. 15,005, features which are shown but not claimed therein being shown and claimed in this application.

What I claim and desire to secure by Letters Patent of the United States is 1. An electric signaling system comprising a source of energy, a signal receiving loop, a resistance, a signal sending loop, an

electromagnet therein, and means controlled by said magnet upon'energization thereof for connecting said loops and said resistance in series with each other and to the source ofenergy and upon deenergization thereof for connecting said signal sending loop directly to the source of energy and thereafter connecting said signal receiving loop directly to the source of energy and shortcircuiting said resistance.

2. An electric signaling system comprising a source of energyya signal receiving loop, a signal. sending loop, an electromag net therein, an open shunt across said signal receiving loop, and means controlled by said magnet upon deenergization thereof for connecting said shunt and said signal sending loop inseries with each other and directlyto the source of energy and there-- after connecting said signal receiving loop directly to the source of energy.

3. An electric signaling system co nprising a source of energy, more than two signal receiving loops, a resistance, a signal sending loop, an electromagnet therein, and means controlled by said magnet upon energization thereof for connecting said loops and said resistance in series with each other and to the source of energy and upon deenergization thereof for connecting said signal sending loop directly to the source of energy and thereafter connecting said signal receiving loops in parallel with each other and directly to the source of energy without reversing the. current through any of said loops and short-circuiting said resistance.

4. An electric signaling system comprising a source of energy, a signalreceiving loop, a signal sendingloop, an electromagnet therein, and means controlled by said magnet upon energization thereof for connecting said loops in series with each other and to the source of energy and upon deenergization thereof for connecting said sig nal sending loop directly to the source of energy and thereafter connecting said signal receiving loop directly to the source of energy.

5. An electric signaling system comprising a source of energy, more than two signal receiving loops, a signal sending loop, an electromagnet therein, and means controlled by said magnet upon energization thereof for connecting said loops in series with each other and to the source of energy and upon deenergization thereof for connecting said signal sendingloop directly to the source of energy and thereafter connecting said signal receiving loops in parallel with each other and directly to the source of energy without reversing the current through any of said loops.

6. An electric signaling system comprising a signal receiving loop, a signal sending loop,

a normally grounded source of energy therefor, an electromagnet connected at one end of said signal sending loop ad acent to the grounded terminal of the source of energy,

a resistance and means controlled by said magnet upon deenergization thereof for connecting the other end of said signal sending loop to the non-grounded terminal of said source of energy through said resistance and thereafter connecting said signal receiving loop directly to the source of energy.

'7. An electric signaling system comprising a source of energy, a signal receiving loop, a first resistance, a signal sending loop, an electromagnet therein, a second resistance, and means controlled by said magnet upon energization thereof for connecting said loops and said firstresistance in series With each other and to the source of energy and upon deenergization thereof for connecting said signal sending loop directly to the source of energy in series With the second resistance and thereafter connecting said signal receiving loop directly to the source of energy and short-circuiting said first resistance.

8. An electric signaling system comprising a source of energy, more than two signal receiving loops, a first resistance, a signal sending loop, an electromagnet therein, a second resistance, and means controlled by said magnet upon energization thereof for connecting said loops and said first resistance in series with each other and to the source of energy and upon deenergization thereof for connecting said signal sending loop directly to the source of energy in series with the second resistance and thereafter connect- With each other and directly to the source through any of said loops and 'sliort :ircuitving said first resistance.

9. In an electric system, the combination of a fuse arranged to be traversed by the current of a plurality of circuits, a resistance in thermal contact With said fuse and arranged to be traversed by the current of one of said plurality of circuits, and a spring adapted to exert tension on said fuse to hold same in contact With said resistance and arranged to disrupt said fuse when it has been softened-byheat from said resistance.

10. In an electric signaling system, the combination of a plurality of signal receiving loops, a fuse arranged to be traversed. by the current of all of said loops, a resistance in thermal contact With said fuse and arranged to be traversed by the current of one of said loops, and a spring adapted to exert tension on said fuse to hold same in contact with said resistance and arranged to disrupt said fuse When it has been softened by heat from said resistance.

11. In an electric system, the combination of a fuse arranged to be traversed by the curcontact with said resistance is of the same polarity as said resistance.

SIMON B, HESS. 

